Computer processors are well known and widely used for a variety of purposes. One application of computer processors is digital signal processing (DSP). By definition, digital signal processing is concerned with the representation of signals by sequences of numbers or symbols and the processing of these signals. DSP has a wide variety of applications and its importance is evident in such fields as pattern recognition, radio communication, telecommunications, radar, biomedical engineering, and many others. With the introduction of digital television, the encoding and decoding of video data gains more and more importance. To save bandwidth, video signals are compressed by removing redundancies. Video compression standards are for example, JPEG, MPEG1 and MPEG2. Data compressing methods are, for example, explained in: Wallace, Gregory K.: The JPEG Still Picture Compression Standard, IEEE Transactions on Consumer Electronics, Vol. 38, No. 1, February, 1992 2!.
As used herein in singular and plural, the term "sample" represents input data, the term "amplitude" represents output data, and the terms "coefficient", "quantizer" and "intermediate result" represents any additional data needed to go from input data to output data.
FIG. 1 illustrates a simplified flow chart diagram of data encoding method 200 according to the prior art. Method 200 is explained in further detail in reference 2!. For convenience of further explanation, keywords are underscored. In transforming step 210, image samples f(i,j) in an image domain are received and transformed by e.g., Forward Discrete Cosine Transformation (FDCT) into amplitudes X(u,v) in a spectral or frequency domain. In quantizing step 220, quantized amplitudes X.sup.Q (u,v) are obtained by dividing amplitudes X(u,v) by quantizers Q(u,v). In zigzagging step 230, quantized amplitudes X.sup.Q (u,v) are re-arranged according to a zigzag path of a predetermined (u,v)-order. In rate controlling step 240, quantized amplitudes X.sup.Q (u,v) having a value of zero are detected. In run-length encoding step 250, pairs X.sup.Q (u,v);(u,v)! of non-zero amplitudes X.sup.Q (u,v) and indices (u,v) are provided as output data. The steps are repeated upon receiving new image samples (line 260).
The present invention seeks to provide an improved method and system for signal encoding which mitigates or avoids well known disadvantages and limitations of the prior art.